* accounts/abi: added documentation

* accounts/abi: reduced usage of arguments.LengthNonIndexed

* accounts/abi: simplified reflection logic

* accounts/abi: moved testjson data into global declaration

* accounts/abi: removed duplicate test cases

* accounts/abi: reworked abi tests

* accounts/abi: added more tests for abi packing

* accounts/abi/bind: refactored base tests

* accounts/abi: run pack tests as subtests

* accounts/abi: removed duplicate tests

* accounts/abi: removed unnused arguments.LengthNonIndexed

Due to refactors to the code, we do not need the arguments.LengthNonIndexed function anymore.
You can still get the length by calling len(arguments.NonIndexed())

* accounts/abi: added type test

* accounts/abi: modified unpack test to pack test

* accounts/abi: length check on arrayTy

* accounts/abi: test invalid abi

* accounts/abi: fixed rebase error

* accounts/abi: fixed rebase errors

* accounts/abi: removed unused definition

* accounts/abi: merged packing/unpacking tests

* accounts/abi: fixed [][][32]bytes encoding

* accounts/abi: added tuple test cases

* accounts/abi: renamed getMockLog -> newMockLog

* accounts/abi: removed duplicate test

* accounts/abi: bools -> booleans